Electrical therapeutical device for internal application



F. J. HART Jan. l5, 1957 ELECTRICAL THERAPEUTICAL DEVICE FOR INTERNAL APPLICATION Filed July l2, 1952 1 N VENTOR United States Patent O ELECTRICAL THERAPEUTICAL DEVICE FOR INTERNAL APPLICATION Fred J. Hart, Salinas, Calif., assignor to Electronic Medical Foundation, San Francisco, Calif., a corporation of California Application July 12, 1952, Serial No. 298,517

S Claims. (Cl. 12S-303.12)

This invention relates broadly to electrica-l therapeutic devices and more particularly to an improved means for heating an internal electrode for use in electro-therapy.

This application is a continuation-impart of my application Serial No. 14,616, filed March l2, 1948, for Electrical Therapeutic Devices and now abandoned.

One of the objects of my invention is to provide a construction of internal electrode for use in electroetherapy which includes a spark generative -of heat and having means for conducting the heat developed by the spark discharge into the hollow interior of the internal electrode for conduction through Athe wall thereof and application over the external surface of the electrode to the patient under treatment.

Another object of my invention is to provide the construction of an electrical therapeutic device in the form of an internal applicator having a thermal switch in the interior thereof operative to successively make and break an electrical circuit through a reactor from a power supply system producing successive spark discharges at periodic intervals generative of heat and including means for conducting the heat from the spark discharge through the walls of the applicator.

Another object `of my invention is `to provide a construction of internal applicator having a hollow interior enclosing a thermally operative periodic switch including a pair of spark electrodes having means associated therewith for conducting heat generated by the spark discharge to the interior Walls of the applicator for distribution over the exterior walls thereof.

Other and further objects of my invention reside in a construction of periodic circuit make and 'break device for internal electrodes and an associated magnetic reactor as set forth more fully in the specication hereinafter following by reference to the accompanying drawings, in which:

Figure l is a schematic diagram of the electrical circuit through the internal electrode and associated magnetic reactor in accordance with my invention; Fig. 2 is an enlarged longitudinal sectional view through the internal electrode and the 4thermal controlled switching system arranged in accordance with my invention, the parts of the switching system being shown in elevation; Fig. 3 is a view similar to the view shown in Fig. 2 with the parts of the switching system illustra-ted in section; Fig. 4 is a View similar to the view shown in Figs. 2 and 3, but illustrating the parts of the switching system in top plan view; Fig. 5 is a transverse sectional View taken substantially on line 5--5 of Fig. 3; Fig. 6 is a transverse secverse sectional view taken substantially on line 6-6 of Fig. 3; and Fig. 7 is a transverse sectional view taken substantially on line 7--7 of Fig. 3.

Referring to the drawings in more detail reference character 1 indicates the hollow internal electrode of my invention formed from heat insulation material and having a hollow interior 2 and a tubular shank 1a terminating in an end portion 3 through which the exible cable 4, which houses electrical conductors 9, '10 and 111,

enters. Within the hollow interior 2 of internal electrode 1, I provide the bimetallic strip 5 capable 4of being tiexed upwardly under conditions of heating and capable of quick restoration to a normal horizontal position upon cessation of heating. The bimetallic strip 5 carries a contact 6 at the end thereof adjacent the hollow interior end of internal electrode 1. A sheath of insulation material 7 surrounds the bimetallic strip 5 and over this insulation material 1 provide a heater wind-ing 8, one end of which connects to the electrical conductor 9 and the other end of which connects to contact 6 on bimetallic strip 5. The bimetallic strip 5 is electriallcy connected at the end `thereof remote from contact 6 with electrical conductor 10 which connects through the magnet-ic reactor 12 with one side of the power supply 14 through control switch 13.

The electrical conductor 9 leading from the heater winding 8 connects to the same side of the power supply 14 as indicated at 9a with the magnetic reactor 12 disposed between the connection 9a and the electrical conductor 10 leading to bimetallic strip 5. The opposite side of the power supply 14 connects through electrical conductor 11 with adjustable contact 25 aligned with coutact 6. Upon closing switch 13 heater winding 8 is energized due to the normally closed path through contacts 6 and 2S leading to the power supply, whereupon heat is supplied from winding 8 to the bimetallic strip 5 resulting the differential expansion of the bimetallic parts of the bimetallic strip 5 and the displacement of contact ii, away from contact 25, thus resulting in the breaking of the circuit between contacts 6 and 25 and the production of a spark discharge which is utilized to convey heat to the interior of electrode l. The electrode 1 is accordingly elevated in temperature for application of heat to a patient. After the contact 6 separates from contact 2S, the circuit through the heater wind-ing 8 is open, thus `enabling the birnetallic strip 5 to cool. When cooled, the `b'unetallic strip 5 restores the contact 6, closing contact Z5, reenergizing heater Winding 8, and recycling the process `steps hereinbefore cited, thus continuing to impart heat t-o the electrode 1.

The transfer of heat from the spark discharge, between contacts 6 and 25, is facilitated by the mounting of 'the thermal switch in the frame structure 1S illustrated in Figs. 2-7 within the hol-low interior 2 of the electrode 1. The frame structure 15 includes a vertically extending portion and a pair of laterally extending portions 16 and 17 adjacent the upper and lower limits of the frame 15 and, at diagonally lopposite corners thereof, the transversely extending portion 16 includes la heat conduction heat transfer portion 16a adapted to establish contact with the interior side Wall of internal electrode 1 for communicating heat thereto at the same Vtime that the switching device is maintained in the required position thereof. The transversely extending portion 16 also provi-des a mounting means for the b.imetallic strip S which is secured thereto by means of the tubular rivet shown at 18 which provides a passage for the end of electrical conductor 9 which is grounded to the transversely yextlending portion 16 of the frame 15, as represented at 8a.

The bimetallic strip 5 is shown wrapped with the insulation material 7, as heretofore explained, which carries the heater winding 8. The transversely extending portion 17 of frame 15 which is disposed in substantially parallel spaced relation to transversely extending portion 16 of frame 15 is provided with a lug 17a which serves to retain the strip of insulation material, represented at 19, in position with respect to frame 15. The strip of insulation material 19 is interposed between the transversely extending portion 17 and the heat conducting member 20. Heat conducting member 20 is maintained in electrically insulated relation to frame 15 by the mounting thereof on insulation strip 19 through the tubular rivet 22. Tubular rivet 22 is insulatingly mounted with respect to frame 15 by means of the insulation member 24 which includes a ilange portion 24a and a sleeve portion 24b that enters an enlarged recess 23 in transversely extending portion 16 of frame structure 15. The tubular rivet 22 extends through insulation material 19 and is secured over heat conducting member 20 forming a mounting means for the heat conducting member 2t). The electrical conductor 11 has the end thereof extending through tubular rivet 22 and soldered at 11a on heat conducting member 20` which also serves as a support for the adjustable contact screw 27 which carries the adjustable contact 25, alignable with Contact 6 on bimetallic strip 5. The adjustable contact screw 2'7 has a slotted head 27a therein for facilitating the adjustment of the contact 25 with respect to contact 6. The insulation strip 19 is apertured at 19a for the passage of the adjustable screw 27 therethrough. The heat conducting member 20 is provided with a head 21 thereon which is shaped to conform with the hollow of the interior of the end of electrode 1 for conducting heat generated by the spark discharge at contacts 6 and 25 to the interior wall of the applicator ll for distribution through the external surface thereof in the treatment of a patient.

The strip of insulation material 19 also serves as a support for a tubular rivet 28 through which the end of the electrical conductor 9 extends and terminates in a soldered connection with a ilexible lead represented at 8a. The terminal thus formed is connected through the flexible lead 8a with the end of the heater winding 8 as shown.

The operation of the heater will be understood from the description hereinbefore given. As the parts of the bimetallic strip diierentially expand under the thermal action of winding 8 the contact 6 separates from contact 25 producing a spark which is increased by the action of magnetic reactor 12. The heat generated by this spark discharge is conducted through heat conducting member 20 and head 21 to the interior wall of applicator 1, thereby heating the external walls of the applicator for use in the treatment of a patient. As the parts of the bimetallic strip 5 cool, contact 6 closes with respect to contact 25 and the spark discharge cycling operation is repeated. Adjustment in the position of the contacts is made by adjusting the position of screw 27. Reactor 12 is permanently connected in series between bimetallic strip 5 and the power supply 14 so that no short circuit can occur. Either winding 8 or reactor 12 are disposed in series between power supply 14 and the contacts 6 and 25 at all times whether the bimetallic strip 5 is in the normal or central or horizontal position, with the contacts 6 and 25 closed or flexed in a position in which contacts 6 and 25 are open. The reactor provides a sufficient load in circuit with the contacts 6 and 25 to insure a substantial spark discharge for imparting heat to the wall of the electrode through the frame structure 15 which contacts with the interior side wall of the electrode at 16a and through the heat conducting members 20 and 21 which contact with the interior wall of the electrode.

While I have described my invention in certain of its embodiments, I realize that modifications may be made and I desire that it be understood that no limitations are intended upon my invention other than may be imposed by the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States, is as follows:

1. In an electrical therapeutic device, a hollow internal applicator having an entry for conductors at one end and being closed at the other end, a thermally'operated switch mounted in said applicator, said switch having make and break contactors mounted in heat conducting relation to the interior wall of said closed end and being adapted for connection to an electrical power supply system and a heat conducting member conductively connected with said thermally operated switch and establishing thermal contact with the internal walls of the closed end of said hollow applicator.

2. In an electrical therapeutic device, a hollow applicator having a conductor entrance at one end and being closed at the other end, a thermally controlled switch member mounted in said applicator adjacent the interior Wall thereof, said switch having make and break contactors mounted in heat conducting relation to the interior wall of closed end of said applicator, a switch winding encircling said switch member, said switch winding being adapted to be connected to an electrical power supply, and a heat conducting member extending between said contactors and the interior of the closed end of said hollow applicator, said switch winding being mounted in heat conducting relation to said applicator for aiding said make and break contactors in supplying heat thereto.

3. In an electrical therapeutic device, a hollow applicator having a conductor entrance at one end and being closed at the other end, a heat conducting frame disposed within the closed end of said applicator, electrically operated switch points mounted on said frame in said applicator close to the interior walls of said closed end and adapted to transmit heat through said frame to the walls of said applicator, a thermally operated member having a winding thereon for controlling the operation of said switch points, said winding being adapted to be connected with a power supply circuit through said switch points and a heat conducting member establishing surface connection at one end with the interior of the closed end of said applicator and supported at the other end on said frame whereby heat from the spark discharge incident to the breaking of current at said switch points is conducted to said applicator, said winding being mounted in heat dissipating relation to said applicator for aiding said electrically operated switch points in supplying heat thereto.

4. An electrical therapeutic device comprising a hollow applicator having a conductor entrance at one end and being closed at the other end, a frame structure mounted within the hollow interior of the applicator, spaced substantially parallel lugs projecting from said frame structure adjacent diagonally opposite ends thereof, a bimetallic thermally responsive member mounted on one of said lugs and projecting in the direction of the other lug in a plane spaced therefrom7 a heater winding adjacent said bi-metallic thermally responsive member for operating said member, a contact carried by the end of said member, an adjustable contact mounted adjacent said -last mentioned lug in insulated relation to the frame and in alignment with the aforesaid contact, said heater winding and said contacts being connectible with a power source whereby a make and break connection is established through said contacts by operation of said thermally responsive member, anda heat transfer device for conducting the heat developed at said contacts and by said heater winding to the interior of the closed end of the hollow applicator.

5. An electrical therapeutic device comprising a hollow internal applicator having a conductor entrance at one end and being closed at the other end, a make and break contactor mounted inside said applicator adjacent the interior closed end thereof, said contactor being adapted to be connected with a power supply circuit, a bi-metallic member extending adjacent the side wall of said applicator for successively opening and closing said contactor for interrupting and completing a circuit through said contactor from the power supply circuit, and a heat transfer member disposed in contact with the interior wall of the closed end of the applicator at one end and disposed in heat conductive connection with said contactor at the other end thereof for conducting the heat developed by the arcing during said make and break operation of saidl contactor to the closed interior wall of the end of said applicator.

6. An electrical therapeutic device comprising a hollow internal applicator having a conductor entrance at one end and being closed at the other end thereof, a make and break contactor located inside the interior of said applicator adjacent the closed end thereof and adapted to be connected with a power supply circuit, means for successively intermpting and completing connections from the power supply circuit through said contactor, and a heat conductive member connected at one end with said contactor and having a head at the other end thereof substantially conforming with the shape of the end of the hollow interior of said applicator extending into heat transfer Contact with the closed interior end wall of said applicator for transferring heat developed by the arcing of said contactor to the closed interior end wall of said applicator.

7. An electrical therapeutic device comprising a hollow internal applicator having a conductor entrance at one end and being closed at the other end thereof, a make and break contactor located inside the closed end of said applicator and adapted to be connected with a power supply circuit, means located inside said applicator for successively interrupting and completing connections from the power supply circuit through said contactor, and a metallic shoe extending from said contactor centrally of the hol low interior of said applicator, said shoe terminating in an enlarged head establishing heat transfer surface contact with the interior closed end wall of said applicator for conductively transferring the heat developed by the arcing of said contactor to the interior closed end wall of said applicator.

8. An electrical therapeutic device comprising a hollow internal applicator having a conductor entrance at one end and being closed at the other end, a make and break :contactor located inside the hollow interior of said applicator adjacent the closed end thereof and adapted to be connected with a power supply circuit, said contactor including a fixed contact and an adjustable contact, a heat conducting member connected at one end with said adjustable Contact, an enlarged shoe carried by the tip of the other end of said heat conducting member and establishing heat conductive surface contact with the interior wall of the closed end of said hollow internal applicator, and means located interiorly of said applicator for successively interrupting and completing a circuit from the power supply circuit through said contactor whereby the heat developed by the make and break operation of said contactor is conducted to the hollow interior wall of said applicator through the tip of said heat conducting member.

References Cited in the file of this patent UNITED STATES PATENTS 771,820 De Forest Oct. l1, 1904 1,272,469 Lidberg July 16, 1918 1,964,732 Homan July 3, 1934 FOREIGN PATENTS 836,839 Germany Apr. 17, 1952 

